Open wounds or rashes on the tibial testing area Active skin infection Recent tibia surgery Abnormal tibia Anatomy Current or previous tibial fracture Body Mass Index >34.9 Hyperparathyroidism or hypoparathyroidism within 5 years Osteitis deformans Renal osteodystrophy Osteomalacia Stroke with total or partial paralysis with residual disability lasting more than 3 months Current or recent (within past 6 months) use of bone-active drugs Drugs under research protocols Chronic use of over the counter antacids